1. Field of the Invention
The present invention relates to an image processing apparatus, an image processing method and a recording medium.
2. Description of the Related Art
These days, in the production printing market, an MFP (Multi Function Peripheral) is often used as a POD (Print On Demand) solution instead of an offset printer. This is because the MFP is strong in small-lot production of various products and short-run production. In general, in an MFP, colors are reproduced by using cyan (C), magenta (M), yellow (Y) and black (K) color materials (toners). The C, M, Y and K are so-called process colors. In raster image processing to generate image data (CMYK data) from a print job, colors are converted into device-dependent CMYK values (device color values) by using an ICC (International Color Consortium) profile to perform printing. On the other hand, in offset printing, printing is sometimes performed by using color (spot color) ink. The colors (spot colors) are different from the process colors. The spot color ink (spot colors) varies depending on ink manufacturers, and hence there are thousands of kinds of spot color ink.
In POD printing, in general, documents are created with RGB or CMYK. However, logos, marks or the like of organizations are sometimes specified by spot colors. Therefore, it has been important for MPFs too to deal with spot colors not only for proofs but also for commercial printing. In order to deal with spot colors, Japanese Patent Application Laid-Open Publication No. 2005-223695 and Japanese Patent Application Laid-Open Publication No. 2005-278074 propose performing color conversion on image data for printing including spot colors, referring to a spot color table in which spot color names are respectively correlated with values of converted colors. According to the publications, when printing is performed, each spot color is converted into a CMYK value by using the spot color table, and the CMYK value is combined with a CMYK value outputted to a printer.
Furthermore, in a workflow of POD, so-called job storage/editing function and reprint function are important. With the functions, image data on which raster image processing and/or color conversion are already performed is temporarily stored in an MFP; trial printing to check an output setting, colors and image positions as a final check before printing is performed; setting change and/or some adjustment (color adjustment) are performed as needed; and then the printing (reprinting) is performed.
However, in such a case where reprinting is performed after spot color adjustment is performed (a spot color table is changed), conventionally, it is necessary to re-send a print job and/or to re-perform raster image processing, and/or it is necessary to store a plurality of spot color data of respective spot colors in addition to normal CMYK data when image data is stored in an MFP, and to combine the plurality of spot color data with the CMYK data when printing (reprinting) is performed. Thus, conventional methods require a large storage region to store data and/or much time to perform processing.